McLaren is threatening to quit F1.

The once-great British team has struggled in its most recent Honda and Renault-powered eras.

Ahead of the crunch meeting with Liberty Media on Tuesday over the 2021 regulations, current boss Zak Brown said F1 in the future needs to be "financially viable" and allow the team to "fight fairly and competitively".

"If it wasn't that, we would seriously have to consider our position in F1," he told the Guardian.

"People throw it out there as a negotiating tactic but this has to be a fiscally responsible, competitive racing team and, if we feel the new rules don't put us in that situation, we would have to review our participation in F1," Brown added.

One sticking point could be that Ferrari is pushing to maintain its position as the most financially favoured team.

Brown said: "We all agree Ferrari is the biggest name and should be remunerated as such but not at the level that it is and you also should not be able to put that money into the racing."

So ahead of the March 26 meeting, and the June deadline for the 2021 rules to be finalised, Brown said he is expecting "fireworks".

"It's negotiation but I am optimistic F1 will do the right things and sign up all ten teams and we will have a much better, more competitive F1 from 2021 onwards," he said.